'FullBallAnimation - By Brad Moore
'Placed into the public domain Oct 2004

   xchg = -10
   ychg = ((int(rnd(0)*8)-3) / (int(rnd(0)*3)+1))

   xloc = 440
   yloc = 80

    NOMAINWIN
    WindowWidth = 515 : WindowHeight = 303
    UpperLeftX = INT((DisplayWidth-WindowWidth)/2)
    UpperLeftY = INT((DisplayHeight-WindowHeight)/2)

graphicbox  #main.gfx, 10, 10, 480, 210
button      #main.go, "Go!",[go],UL, 385, 230, 105, 25
statictext  #main.st1, "Speed: nn", 10, 233, 100, 25
statictext  #main.st3, "Y-change: nn", 160, 233, 200, 25

Open "Window Title" for Window as #main
    #main "trapclose [quit]"
    #main.gfx "down; fill White; flush"
    #main "font ms_sans_serif 10"

[loop]
    Wait

[quit]
    close #main : END

[go]
    #main.gfx "color white"
    timer 50 , [move]
    wait
    
    
[move]
    #main.st1 "Speed: " + str$(abs(xchg))
    #main.st3 "Y-change: " + str$(abs(ychg))
    oldx = xloc
    oldy = yloc
    xloc = xloc + xchg
    yloc = yloc + ychg
    'there is a weird bug that occasionally occurs where y can keep getting smaller
    'or it can keep getting bigger - fix it here
    if yloc < 0 then yloc = 0
    if yloc > 210 then yloc = 210
    #main.gfx "backcolor white"
    #main.gfx "up; goto ";oldx;" ";int(oldy);"; down; circlefilled 10"
    #main.gfx "backcolor red"
    #main.gfx "up; goto ";xloc;" ";int(yloc);"; down; circlefilled 8"
    
    if yloc < 2 or yloc > 208 then 
        ychg = ychg * -1
    end if
    if xloc < -2 or xloc > 482 then [changedirection]
    wait


[changedirection]
    'adjust the ball speed (x direction of travel)
    ballspeed = int(rnd(0)*4)-1
    direction = -1
    if xchg < 0 then direction = 1
    xchg = abs(xchg)    
    xchg = xchg + ballspeed
    if xchg < 8 then xchg = 8
    if xchg > 26 then xchg = 26
    xchg = xchg * direction

    'adjust the ball's defelction angle (y direction of travel)
    direction = 1
    if ychg < 0 then direction = -1
    ychg = abs(ychg)
    ychg = ychg + ((int(rnd(0)*9)-3) / (int(rnd(0)*3)+1))
    if ychg < 0 then ychg = 0
    if ychg > 10 then ychg = 11.25
    ychg = ychg * direction
    
    wait

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